SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd25a28b1b1b5b95a11f13f398f109ebbb771bdf6650f9d0833b259c07a89d993' 
  AND token = 'yF2MgxjJ3mVvxUPAWVrOLJTPbFGA3vmdtwlNXEvVAK8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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