SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3a22fd8d98d26929bfbc4360750031c2c5ee5a0ffaccdbfda1a7e0d5fd1c2ee1' 
  AND token = 'nWzasYZWm9YMTJMkTIWOgmjhXvnly6aJsUz/USyehG4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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