SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '0992fdeed50e295d4b0a6ce0c83e249052ab1b003f824e24ebe8b6c3e4e1c7f3' 
  AND token = 'mOtMzTpFD/3gkOOVwopqWqRVS26jhK66DPq84xDdl2k=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00042

JSON explain

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