SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '34360cc82e1d261ee6ce043ccfd68582a5e932adfc632ae2003b223b35b05fe2' 
  AND token = 'oV2rc3uVVGxeKHaetqIBKGr0d/KGpS97ZaNGbsPmNXU=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00029

JSON explain

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