SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'cc3ce763de225ac7b1bc176f692ae5781f2eb9a549991d3fca58c622fb415400' 
  AND token = 'qptPHwXdGD/0FaEa6joYxS1bsUIjNL6Suavw2saf88s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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