SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = 'e69048925543ab1c6df69b731cf0f3c2a7497fec95360112f2bd4109ad397fee' 
  AND token = '7QJ/OV9qbPgHvJj+NaKx7mDM7j15IfdC0+IExjjGBkk=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00034

JSON explain

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