SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'fe267299a22b060ff70739009cbb960b807fc2a366aefd985dee29247234ed37' 
  AND token = 'hRdJwKCFA040IjEFsRLRvUNArcmMrXHG8HzGbdVxmYI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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