SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '6e0edeec737157d97e3174ac5e58abf6287a265cf97df1e275abfa6f20130845' 
  AND token = 'Hpa3jYYOuUqFj1RWU/PEndxmd74AA3txHBDTI+aSFv0=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00018

JSON explain

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