SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '341997b39029974994df6821c0202e112be7ea1fdd3d577676d6e4f33963aec2' 
  AND token = 'w8gXu5khdd23x24IvlWprvIn1Eg+hli4kLuXiuhspzA=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00041

JSON explain

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