SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '3d841e937cf2d2d9822ec240c2cf2cc985b7881a9b148cbc95c2d4dab0ab44a9' 
  AND token = 'm3bhZ1xMVzA/W4Zgm9JLqFVQwWx/LcGL3PgXDBYgdH8=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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