SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '48de8caaf76293c2eb544216613662550f8d2e66d02fbe1b724829018e8969df' 
  AND token = 'x4B5sOJaVYexq38YjWpoLIaZohZRkkKHz/I3kYR01xU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00031

JSON explain

{
  "query_block": {
    "select_id": 1,
    "table": {
      "message": "Impossible WHERE noticed after reading const tables"
    }
  }
}