SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '982cb3dae8991547bac1360bd92dc6cb937a99ebe92f068e7b198b7e50bfc638' 
  AND token = '57rtNR9lQnS0w/WO4M+gajfWVaDsBFJvkh2gO5FzNtg=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

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