SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '531a50aab5469fe5dfcf9cfbe230bc0ffdcf3bcb55727ec97e299fa0eb0a3c48' 
  AND token = 'pQHHsVfWmZ5m/1622RJwZ6sTudTaMJEkBLnCsoYadMc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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