SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'f46570aaba641abb6caecd72cbe52b8ecaafdb12974aa2d613f64d9d2614315e' 
  AND token = '2oP2NAsyPmGtGnSas4QHGTVxFN6VNDcLJLYCrhlQ8+M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00035

JSON explain

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