SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '545e356ac65ab05f930600e07fc1f637ca00274521b8741d6468d0790af093e5' 
  AND token = 'vXTtyOpUPp1jLJcPIpzdeVSfWJuYM8eK/EYQF7nOcfA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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