SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '3d00956a9982fc9b240a361fe3767a0c4652851da5192f37bf92cab7eea1af48' 
  AND token = 'WEghU+shL5Aw9/iOACQ+DIef/SeKXpb1NOXgJHnhzmU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00020

JSON explain

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