SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '2d79d5c1bbc3986f4c327d9f20f91694913f95caccab030e27afff86d9ffa354' 
  AND token = 'EvN0H/Ta4n1DsngqPMyIK2XTXxHlsoOFkwxwSN1+0+s=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00047

JSON explain

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