SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '7c720db70b751f3749aa108a3a932265cfa04739ed00c504a676bb5ece76298e' 
  AND token = 'eayBmSttrKieKNVpn+tDfQXBL1uGglLKq/WrhPVebJA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

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