SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3f97643137dc09ca7fcb06e83561d4d4115867e67ea7b82b052f8659241624cf' 
  AND token = 'LbeY+NjEvR1G0SKCwuIo8sNKWpkmP7DVmsBAry4t1lM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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