SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2307cff02dce958cb62361a8792b31ffa7825a96b371fe9d35791c4e4ebfd34a' 
  AND token = '8DqyIpH27eS9uqCRI5Vh3p59QNrm0bESSiBtScjdp7s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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