SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'fe16d569aa3cbf0731f57e43e6955d33bb8d129f30865ca2d3c2cb98a02a7052' 
  AND token = 'RA3Laj5ANsrp08n/boN8Io31qF46fwJEEV1D8P5LP3M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}