SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '1979c810a2f89319b96d53dda9d8ca9a933a20665243afd4036fa60c0b8abe9d' 
  AND token = 'VUxp6pEkC0T2QB8SgRQWLOY55c8SaYtJYQhZUL15CaM=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00014

JSON explain

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