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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a6d76c0d8ca9d0be067e86236bf6d57d714135eebaabbd2fc360fdc506121b07' 
  AND token = 'bhKgFwHMsQdEZH5sumEm0AaYz0Puv5UbXH+9wVUiwmE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}