SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '26badb1fd33c5524aaaed27b6fd8feed667d04665b3e5f2050d1d56d2aeccf18' 
  AND token = 'kEcrKXOKeXnurdnuRguQTA9ftHcdrhYD6YnCVQIwriU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00032

JSON explain

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