SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'e468bf417bbc0943f990825904e6dc3c4135690c505b56b5184c82eb065b6470' 
  AND token = 'WlK6bxYOJpwXV5s2yTZ+pFwQULKevP9e/3qVh5sRcuE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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