SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '4bf0a9d861f618c3d47a820db49a3b671e469b387a7d1a6b2a9571e64aa0a84b' 
  AND token = '+r67ooFXvnwsXwyOMgg8JHAT96xkc7yVp8s/vOZnbJs=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00024

JSON explain

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