SELECT 
  1 
FROM 
  cscart_multi_declock_keys 
WHERE 
  key_id = 'bbdb0012b98b6335889c75fc069cddd02293c22fd1dcb728660979d7ee01ee46' 
  AND token = 'JovzJlHUoWsAQRVOE17PICM97iw8O62bipfw2uDz3oc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00023

JSON explain

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