SELECT 
  1 
FROM 
  cscart_aprillock_keys 
WHERE 
  key_id = '91641608c333da90ce1151196070cbd21ff2a73a808dbabac801c4117d3b0b73' 
  AND token = 'UmBf7AyobDlmpYPKQyQiy7rNbuk4Ty4IWfclx0vGZBc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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