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SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '9383f5cd074ca289a7ad573ee041eaf15f1ef31dccd47e6d537a9b58f4f5850a' 
  AND token = 'QWTYu1Gsh8Vi9YfcEcTN/rH7m/2TvR9JJYw6qT+O+D8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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