SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8cac1fed0dda185c1fd9aab1a3919958077679fb03fb2cbd39858e2cb5dd5541' 
  AND token = '/IljEHInRweEmAd6BsvUxVBiVxF4jQmXGrLXPxZsmqM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00030

JSON explain

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