SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = 'bc3df660d97f489905e1c2c77d57c58be3ba8cb68346cd2549b12969245217f6' 
  AND token = 'XWedDk8WeZIibShnLGRRwpo2FysrjL1GmFSI4ifhl1M=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00021

JSON explain

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