SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cfaeda04844d7217cb06640967ad22514e67199526d7b5dc42a3f1544c00f16' 
  AND token = 'eYt/XQyNwgH2X/WEFdfechlfMVgdbXCKSVDwMGMvBAc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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