SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'd5fd229c910fa19587d01327eef7c9355af4e4224fd6582bbde0920fbaddde3c' 
  AND token = 'f03PcpS6MJAO6t7ruYtn+FBWsaChOg79AIAvn5cLfv4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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