SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '8b43c57b9c07159a0504dfdcf8a6fcdc9df7b2cfdc5726ac0332b94e16dbc553' 
  AND token = 'TuoH6FQ1rRKQtqKxoFswfZ+TebuJqUHURNk+vx+hfXE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00033

JSON explain

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