SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'ea67d9d76768037da7db1383f7c8513dec171c9970eb69b57b0380cce47cf339' 
  AND token = 'QXJGv9V0EWH79hE+vuCk2VcLUgWHR42JelbU+tSFqkY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00060

JSON explain

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