SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '36a186984ddb20fde81ae809461481d492ad321f816b44538fdd03ce3ca8cbc7' 
  AND token = 'D0lOz7gfuc0UEhAOroEBL4Y0yG9wwYNFQDIpewUn9yA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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