SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ac21892ba1599072cce6b88613cbcdd10987f728751bafb5e9708af7fe377a1e' 
  AND token = 'PwDlG13ly0CQ83vRmulM9/o/XbzUdx8SPkDNOvRsV14=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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