SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'c5dc95cd59ce722e4213947424515551ca97aa7caf2d6584831bf779e2ad87db' 
  AND token = 'UBJIharI6Y0C0qgNLqVio+olXr/D7lq4WKjSgN9rrzM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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