SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e129e9299f8e5c46caa71473c755c087fa29e8c347b2312002217c4b820365d6' 
  AND token = 'dCk3XJVVyNwFkYADukgopPGYYmhlYYaQXjcSgSsiXz8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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