SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5f034ecb7e93790252e088ba946278023432dfc684c78a466eb3e77921816958' 
  AND token = 'U4DUccHYr4LVqyEE6t9s98FcyXuCZ6IzqmCDYmZxK8Q=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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