SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '31c259840db6e6e5d22ea33b2998cf432cc36e6217278fdb79e25d09fcec1ef3' 
  AND token = 'TNAMKnTILNQnOY26IULq/cCGOiCIQLVWpk3arAFGt2g=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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