SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'de347fcd2230b25074ed90264d08fa0608c0ef0987d5b628452bfe0fd2668863' 
  AND token = 'Y0aRZ8qKJICaMqZgKpQZZI9WfDld7lU9qIZLwUogPKI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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