SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '6f8f1dea1439fa1355fde1f7a180f8a4796d8b7d3951e5abd78aa281c17440e8' 
  AND token = 'IWclMzjtuLQZP/Yw/0XRNnw1wh/Pvjh/2GusNH0fisE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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