SELECT 
  1 
FROM 
  cscart_june_setuplock_keys 
WHERE 
  key_id = 'f038b50c7704d38395268168e39dd5b3172ba9fc70db4ae1f676da1ae850f372' 
  AND token = 'Tk7CE5Z7GVXfH44hUy3+yLx4eLJkOSdTDK+F8ULELsI=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00026

JSON explain

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