SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1d25275bde611950e57e0c7a31738b4b6c234302eb73475a983aa51782339075' 
  AND token = 'AKPaHIDacyjhS0wGZQUbJef+HXuVfMz949R0fQt2SkI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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