SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd48dcbbbacaa602c82a122526ed4b77b23997a1bbcea38e4bd83f36462da8222' 
  AND token = 'ARNJuWH0sXIbQBXCUoYY2EXa3og0voOTxQ6VCtjGB8E=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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