SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8489203ddf97f140997c5d51d561f1b63e1df10aa3e5b77de5bf0a412e6823cd' 
  AND token = 'BSY3qElIRVQlRhmgWHF8fBlxIjDvPVuu8p1ftAiRYik=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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