SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4c389e1efd712dfaddcd60b210108f00ff78c4e46db6691d54b6f768316c1ffe' 
  AND token = 'peJX/JDhK+lIhGYwjnFlfULpODV/VP+pqXwo5fuI8yc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00043

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}