SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '4caced8df6757bfa25d24142d0566c65a6214fb851e76a4ba9be985de5beb588' 
  AND token = '3P+bTKZgh6x0kPUoc72vMbQHUGWTSpb+d24iibabJcc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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