SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c9491c63bfd461a7adcafb7d058c3ac7ba540f56f498f05b21c8f1697706da0b' 
  AND token = 'ISu/KHOFHbN1j8t1MH0A7GiHk+WBu+BC7g27B1xK9+A=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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