SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '70fb5111f075bdee7f138918caa7791ad39f46594d6b6cf19ee6104c74eeda04' 
  AND token = '5UYMg7YHnIlCSCcIRf7ecacreKA++jf7/I2sRdq814M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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