Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '421d57aa423672eec25587d4fa2b8464f9f1fb2cadbdf1145e28f251c8a046db' 
  AND token = 'gTdi5qqSinvvzRcnsiGFMu297FS6UEbgklTQr1GIGAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00019

JSON explain

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