SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3fe12812f507620c6d2f1a035c90139341952fb9b46f5a2f93c9db719fc2b313' 
  AND token = 'ZHrRl+g8q5Ghw9iPKWadwNRnVouG8YuFZ/9eUX9l9e4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00016

JSON explain

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