SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '8d0a1fe18173da9458d8e3a272b10ba398b5366b36d3cda9af75bdf1142c598f' 
  AND token = 'ywF5L/LM4CkNoYj21gonhUP4sCKaMAgAOnUs/PCDV+o=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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