SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'aa12f59072571d782b62467f233b929b583f4300d7b8592ce6fe37fb895b24ff' 
  AND token = 'A8UZbITvSYpPz8mZhN5w69LpHJd/MiTMtyHXjUlV3rw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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