SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f1a98f9ab7c2f4b7ef0d3e4fed51d3f373c6640d9159f02c6f0f7356e6f295b6' 
  AND token = 'VvujahBHQqXy+H43KVuIGjeQVyIolzuEycYZOUhLYKA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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