SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6492631e8cc073e1b00366f59c1098ab5f3cf19312c6cb49c8833477ae79a6ab' 
  AND token = 'QUWhvuzBhJZRv86rxqOXNtGucKGYoTCcnKFa0+Hkpis=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00015

JSON explain

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