SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'a11b5b79b88094472090b4e579679490652f9c0b23335bd0d41b543b1bd7ffea' 
  AND token = 'tTYUFWNeMt7dhvAbn1M+aDUMiKzoejSdpva6/cWYuvE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00036

JSON explain

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