SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f271404aac867c4ebf7ef9137c59d2848acdc147f633adfc78daa7de29734195' 
  AND token = '3Fl+HOo0YTgrc9xYmIBiJqtxIg5jkYwa/55Cz44ofVc=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

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