SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '80ba11b10d4d4c09f44cd16eb53d046e45a728dfd055b7df888bdf432578e9cc' 
  AND token = 'TZLnkC+TRxCoeNAmzvkkpoWeUJKlF/wwAnsN1KZTzBE=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00017

JSON explain

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