SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '709cb8b091f324aa3a53e446487c9bd4eb7b7b08de8e5f7a293b4a1661ac8683' 
  AND token = 'QxSDFzwBm0fGGG0ls3LWcYh34KlQHIF+M5/mE0AghE0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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