SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0a793dc877bddf46c91801202529596c54bbd8a2d1639a87d4803736b776ca1b' 
  AND token = 'IrEPbsIdWpN0w+CTQuLdoZWh5dlB/baOIz6vVy8UJdw=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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