SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '880444b931ddb0f061df0ff567792b529d32c8d1ed02c39f0a3542baf7273826' 
  AND token = 'WhmPGuWEqzvXyvH/N86Y9G7rrLL+6Ac1m1kZEcWfHUU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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