Sandbox

SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ec66307990f15ce1bef4e4cb1ce719fdb2341524f0df0b56daeac694d7fe20ca' 
  AND token = 'NQ2JzQ70Z6rWsBgkFCkYNQy+p+NQecrFSvuY2IL1Qqg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00027

JSON explain

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