SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '051493476f58bd1cb1d1cb0705c60fe023efab90d6837469467b3457178d5b89' 
  AND token = 'BcSFTGQ39rzRUP0Zm2EQFrZJutIMWplQKteM2vbuaSI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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