SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '44d79282b9e7f1d9fc3b2fd83dd024ae87d1d76c630a1d50b91c8274664b632d' 
  AND token = 'U8w3+axkdUxzHN1V+tcgR/lAg1B26MbPSvYyGrpmoCY=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00022

JSON explain

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